Electronic Thermal Overload Protection For Braking Resistor; External Braking Resistors; Standard Models - Fuji Electric FRN0001C2S-2A FRN0002C2S-2A FRN0004C2S-2A FRN0006C2S-2A FRN0010C2S-2A FRN0012C2S-2A FRN0020C2S-2A FRN0025C2S-2A FRN0033C2S-2A FR Instruction Manual

F50, F51

Electronic Thermal Overload Protection for Braking Resistor

(Discharging capability and Allowable average loss)
A braking resistor can be mounted on inverters of 0.4 kW or above.
These function codes specify the electronic thermal overload protection feature for the
braking resistor.
Set F50 and F51 data to the discharging capability and allowable average loss, respectively.
Since those values differ depending on the specifications of the braking resistor, refer to the
tables given below or calculate them according to the expressions given in the FRENIC-Mini
User's Manual (24A7-E-0023), Chapter 9 "FUNCTION CODES."
Depending on the thermal marginal characteristics of the braking resistor, the
electronic thermal overload protection feature may act so that the inverter issues
the overheat protection alarm
enough. If it happens, review the relationship between the performance index of the
braking resistor and settings of related function codes.
The tables below list the discharging capability and allowable average loss of the braking
resistor. These values depend upon the inverter and braking resistor models.


External Braking Resistors

Standard models

The thermal sensor relay mounted on the braking resistor acts as a thermal protector of the
motor for overheat, so assign an "Enable external alarm trip" terminal command THR to any of
digital input terminals [X1] to [X3], [FWD] and [REV] and connect that terminal and its common
terminal to braking resistor's terminals 2 and 1.
To protect the motor from overheat without using the thermal sensor relay mounted on the
braking resistor, configure the electronic thermal overload protection facility by setting F50
and F51 data to the discharging capability and allowable average loss values listed below,
respectively.
dbh
even if the actual temperature rise is not
5-45